# US 7,004,588 B2 · Planetarium and point light source for use in same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,004,588 B2 - Document ID: US7004588B2 - Status: Granted - Kind: B2 - Application number: 10/461,033 - Filed: 2003-06-13 - Published: 2004-01-22 - Granted: 2006-02-28 - Earliest claimed: 2002-07-18 - Assignees: Learning Technologies, Inc. - Inventors: Phillip M. Sadler - Web page: https://patentgrep.com/patent/US7004588B2 ## CPC - G02B 6/0096: {the lights guides being of the hollow type} - G03B 21/2026: {Gas discharge type light sources, e.g. arcs} - G03B 21/208: {Homogenising, shaping of the illumination light} - G09B 27/04: Star maps - G02B 13/06: Panoramic objectives; So-called "sky lenses" {including panoramic objectives having reflecting surfaces} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - G09B: EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS (devices for psychotechnics or for testing reaction times A61B5/16; games, sports, amusements A63; projectors, projector screens G03B) ## Abstract Featured is a portable planetarium device suitable for use in projecting clear bright images of stars, planets, and other celestial objects onto a curved viewing surface. The portable planetarium devices of the invention comprise a point light source generators, a light dispersing lens assembly, and an opaque enclosure having transparent domains surrounding the light dispersing lens assembly. Also featured is a portable point light source comprising a light source, a light collection element and a light conducting conduit suitable for use in providing high intensity light with a small cross-sectional area. ## Claims ### Claim 1 A planetarium projector comprising: a point light source having substantially symmetric light intensity and an apparent cross-section of less than about 2 mm which is capable of generating a beam of high-intensity light having a cone angle θ; an enclosure having opaque regions and transparent regions that correspond to locations of individual celestial stars, wherein the enclosure includes an inner surface and an outer surface; and a light dispersing lens assembly disposed within the enclosure such that the beam of light having a cone angle θ from the point light source enters the light dispersing lens assembly and a beam of light having a cone angle θ′ exits the light dispersing lens assembly wherein θ<θ′ and the beam of light exiting said light dispersing lens assembly fully illuminates the inner surface of said enclosure. ### Claim 2 (depends on 1) A planetarium projector of claim 1, which further comprises an elliptical mirror, a dual paraboloid reflector system, a lens, or a combination thereof, wherein the point light source is situated at a first focus of the elliptical mirror, dual paraboloid reflector system, lens or a combination thereof such that a substantial portion of the light generated by the point light source is concentrated at a second focus of the elliptical mirror, dual paraboloid reflector system, or lens. ### Claim 3 (depends on 2) A planetarium projector of claim 2, further comprising a light-conducting conduit which is interposed between the point light source and the light dispersing lens assembly such that a proximal end of the light-conducting conduit is disposed at the second focus of the elliptical mirror, dual paraboloid reflector system, lens or combination thereof and a distal end of the light-conducting conduit is disposed adjacent to the light dispersing lens assembly. ### Claim 4 (depends on 3) A planetarium projector of claim 3, wherein substantially all of the beam of light from the point light source which enters into the light dispersing lens assembly passes through the light-conducting conduit. ### Claim 5 (depends on 2) A planetarium projector of claim 2, further comprising a light-conducting conduit which is interposed between the point light source and the light dispersing lens assembly having a proximal end of the light-conducting conduit is situated at the second focus of the elliptical mirror or the dual paraboloid reflector system and a distal end of the light-conducting conduit is adjacent to the light dispersing lens assembly such that light directed to the second focus of the elliptical mirror or dual paraboloid reflector system is conducted by the light conducting conduit to the light dispersing lens assembly situated at the distal end of the light-conducting conduit. ### Claim 6 (depends on 3, 5) A planetarium projector of claim 3 or 5, wherein the light-conducting conduit is a fiber optic cable, a bundle of fiber optic cables or a coherent optical bundle. ### Claim 7 (depends on 1) A planetarium projector of claim 1, wherein the beam of light having a cone angle θ has a substantially uniform intensity throughout the cross-section of the beam of light. ### Claim 8 (depends on 1, 2) A planetarium projector of any one of claim 1, 2, or 5 further comprising a variable diameter aperture interposed between the point light source and the light dispersing lens assembly such that the apparent size of the point light source may be varied by modulating the diameter of the variable diameter aperture. ### Claim 9 (depends on 1) A planetarium projector of claim 1 wherein the light dispersing lens assembly comprises at least one optical element capable of dispersing an incident beam of light. ### Claim 10 (depends on 9) A planetarium projector of claim 9, wherein the light dispersing lens assembly comprises at least one fish eye lens, one divergent gradient index lens or one parabolic concentrator. ### Claim 11 (depends on 1) A planetarium projector of claim 1, wherein the apparent cross-section of the point light source is less than about 1.0 mm. ### Claim 12 (depends on 1) A planetarium projector of claim 1, wherein the apparent cross-section of the point light source is less than about 0.5 mm. ### Claim 13 (depends on 1) A planetarium projector of claim 1, wherein the apparent cross-section of the point light source is less than about 0.25 mm. ### Claim 14 (depends on 1) A planetarium projector of claim 1, wherein the point light source generates at least 250 lumens of light. ### Claim 15 (depends on 1) A planetarium projector of claim 1, wherein the point light source generates at least 500 lumens of light, and wherein the apparent cross-section of the point light source is less than about 0.5 mm. ### Claim 16 A planetarium projector comprising: a point light source having substantially symmetric light intensity and an apparent cross-section of less than about 0.5 mm which is capable of generating a beam of high-intensity beam light having a cone angle θ; an elliptical mirror or a dual paraboloid reflector system, wherein the point light source is situated at a first focus of the elliptical mirror or the dual paraboloid reflector system such that a substantial portion of the light generated by the point light source is concentrated at a second focus of the elliptical mirror or the dual paraboloid reflector system; an enclosure having opaque regions and transparent regions that correspond to locations of individual celestial stars, wherein the enclosure includes an inner surface and an outer surface; a light dispersing lens assembly disposed within the enclosure such that the beam of light having a cone angle e from the point light source enters the light dispersing lens assembly and a beam of light having a cone angle θ exits the light dispersing lens assembly wherein θ<θ′ and the beam of light exiting said light dispersing lens assembly fully illuminates the inner surface of said enclosure; and a light-conducting conduit which is interposed between the point light source and the light dispersing lens assembly such that a proximal end of the light-conducting conduit is disposed at the second focus of the elliptical mirror or the dual paraboloid reflector system and a distal end of the light-conducting conduit is disposed adjacent to the light dispersing lens assembly such that substantially all of the light from the point light source which enters into the light dispersing lens assembly passes through the light-conducting conduit. ### Claim 17 (depends on 16) A planetarium projector of claim 16, wherein the light dispersing lens assembly comprises at least one fish eye lens, one divergent gradient index lens or one parabolic concentrator.